The potentials of seaweed

Seaweeds differ from terrestrial plants in many ways. This applies also for the composition and structure of the biomass. Thus, seaweed is an interesting source not only for food, but also for the production of fine chemicals and new bio-based materials. Farming seaweed could also improve water quality and contribute to a better marine environment.

Today, almost 280 million tons of polymers are produced annually world-wide. Most of them are fossil-based. If only a fraction could be replaced by renewable counterparts it would still be an important contribution to the societal goal of a sustainable lifestyle. Seaweed carbohydrates have a unique compositional profile. This makes them highly interesting for the production of bio-based polymers, e.g. bioplastics, gums and other functional biomaterials.

Vegetable food ingredientsBesides carbohydrates, seaweeds are also rich with proteins, long chain polyunsaturated lipids, antioxidants, vitamins and essential minerals. Because of the present desire to decrease dependence on animal-derived nutrient sources, the demand for vegetable alternatives is steadily increasing. Here, seaweed provides a promising base.

”Green” antioxidantsSeaweed derived antioxidants and pigments may be used to replace synthetic food additives with natural extracts. Another interesting application is in lipid-based technical products, e.g. biodiesel, to prevent the attack by free radicals and following rancidification.

Improved environmentsIn contrast to terrestrial systems, seaweed cultivation is not associated with negative environmental consequences from the use of fertilizers, pesticides and freshwater irrigation. On the contrary, seaweed farms can significantly contribute to the remediation of eutrophicated coastal waters. This is due to their direct uptake of dissolved nutrients from the seawater.

Increased biodiversitySeaweed beds constitute an attractive biotope for other marine organisms. In this way, cultivations may contribute to increased biodiversity and fish populations. Furthermore, large seaweed beds are effective carbon sinks, and seaweed farming has been suggested as a way to mitigate global warming.

Asian traditionsNatural populations of seaweed have been harvested and used by man for a long time. Today, more than 90 percent of the algal biomass comes from cultivations. The production is dominated by Asian countries, in particular China, Japan, North & South Korea, and the Philippines.

Promising futureSeaweed cultivation is the fastest growing subsector of global aquaculture. In terms of biomass aquatic macrophytes now account for more than 50 pecent of marine aquaculture. In spite of our long coast, aquaculture is still very minor in Sweden. This is especially true for the cultivation of aquatic macrophytes. But the interest for seaweed is growing in Western countries and the prospects for a future seaweed industry is promising.